In recent days, the question surrounding Syria and its alleged use of chemical weapons appears to have shifted from did they do it to how soon and how forcefully should the U.S. and its allies respond to the deed? Keep in mind this sense of certainty among U.S. officials comes with U.N. weapons inspectors still on the ground in Syria - their search a work in progress. Video of dead and wounded Syrians being brought to clinics has certainly played a part.

Today, news outlets, including Foreign Policy, reported another piece of evidence that appears to have swayed policymakers: that intelligence services intercepted phone conversations - just hours after the chemical attack near Damascus - between Syrian government officials. We're going to hear now from one of the few people in government who's actually been briefed on all the evidence. Republican Mike Rogers of Michigan is chairman of the House Permanent Select Committee on Intelligence. Welcome to the program once again.

REPRESENTATIVE MIKE ROGERS: Robert, thanks for having me.

SIEGEL: As I said, you've been briefed. Is the evidence against Bashar al-Assad and the Syrian regime incontrovertible?

ROGERS: Well, I'm not sure to say it's incontrovertible. I think it's certainly convincing, if not compelling, given the history. And remember, this isn't the first chemical weapon use by the Syrian regime. There have been others. Quantity is smaller. It didn't raise the same level of public attention as this particular event that took the lives of some 1,300 women and children and men, civilians. And so the very public nature of this and the very size and scope of it has brought more attention to this issue.

SIEGEL: But, first, is there evidence that nerve agent, not just some toxic or fatal substance, but nerve agent or sarin gas was used?

ROGERS: Well, I can tell you that there are still some forensic evidence review under way to determine exactly what it is, but it is very clear that it was a chemical agent of some nature.

SIEGEL: Is it clear that it was delivered by some system, say, a rocket, something that only the Syrian government and not the rebels would have?

ROGERS: Well, it's clear by the size and scope of it and, again, with the other evidence that we have that the regime was involved in the delivery of this particular chemical agent.

SIEGEL: But when we say the evidence that we have, we're not talking yet about a crater being identified that was where the rocket struck or fragments of the rocket?

ROGERS: Well, there is multiple ways that they can deliver a chemical weapon like this. You know, there can be airbursts. There can be groundbursts. There can be personal relief. There are other several different ways that you can deliver a chemical agent to have this kind of an impact. Again, when I look at the totality of the evidence that we have, I do believe that it's convincing that they, in fact, did use chemical weapons.

SIEGEL: I should just check. Your first answer to me could be heard two different ways. I want to make sure that I heard it right.

ROGERS: Yeah.

SIEGEL: You say the evidence is convincing, if not compelling.

ROGERS: Right.

SIEGEL: Did you mean it is convincing and compelling, or it's somewhere short of what...

ROGERS: Oh, it certainly is - it's convincing to me. I think to some, it would be compelling, given the strength of certain streams of information that have been made available.

SIEGEL: And these reports of intercepting a telephone communication, according to some sources, an Israeli military intelligence intercept. According to one source, a panicky conversation after this attack actually occurred. Does this at least square with the sort of thing that you were told about in your briefing?

ROGERS: Well, I wouldn't be able to acknowledge that the source or the method of how all the information that we used to come to a conclusion would be obtained. But you can know that this is a whole host of avenues of sources that would lead me to the conclusion that it's convincing evidence.

SIEGEL: Let me just very plainly then run the Syrian and Russian take on this past you and you tell me if it is even conceivable, which is Syrian rebel groups, perhaps jihadists, having heard that the U.S. has established a red line, which is use of chemical weapons, get a hold of chemical weapons, use it, use those weapons as agent provocateurs and are responsible for something, knowing it would be blamed on the Syrian government. That's the case. Is that remotely possible, or is it disproved by the evidence that you've seen?

ROGERS: It's not improbable that that could be case, and that is why there is indeed caution as you approach the evidence that you have to make sure that, in fact, if you believe it's the regime, you have evidence to be able sustain your case that it is, in fact, the regime that has done it.

SIEGEL: Chairman Rogers, you've - as you've said, there's a problem here about disclosing sources and methods. But presumably, the president will describe to the public sometime soon his certainty that justifies taking action against Syria. How far can he go? How far should he go in convincing Americans that whatever you hear from Russians is not so? The bad intelligence we had about Iraq, it's different this time. How far can he go? How far must he go in that statement?

ROGERS: Well, I think he's boxed himself in a corner. I think he's probably going to have to go further than, in some cases, would be desirable only in the sense that you want to protect the intelligence community's ability to continue to get information of value. And part of that is there has been, unfortunately, no consultation or advice or consent from Congress on the way forward after this particular event. I think that is a very, very, very dangerous decision for the president to make if he continues to want to build support for this, number one.

SIEGEL: You're saying there hasn't been consultation on, to put it simply, the strikes that we anticipate now, the attack against Syria.

ROGERS: Well, the way forward, yeah, what are the actions? And I do believe that there are consequences for not doing anything just like I believe there are serious consequences for doing something. But that's why I think the president - why I think he's legally obligated, let alone morally obligated to consult with Congress and at least the national security committees. I think the president's making a mistake by not doing that. I think he's going to have to talk to the American people.

He's a little bit behind the eight ball on this because he as been so silent on it for so long that it's going to mean, I think, a more difficult road for him to do candidly. What I think is important is that you cannot draw a red line in the sand and put U.S. credibility at risk and then not follow through with your red-line rhetoric. I think that's dangerous for other countries' decisions that they might make about the strength or weakness of U.S. national security.

SIEGEL: Congressman Rogers, thank you very much for talking with us today.

ROGERS: Robert, thank you so much for having me.

SIEGEL: That's Mike Rogers, Republican of Michigan. He's chairman of the House Permanent Select Committee on Intelligence. And by virtue of that position, he is one of those members who has been briefed and shown the intelligence that justifies the administration's confidence that this indeed was a use of chemical weapons by the Syrian government.